Conway argues that leaving off the parens from user-defined subroutines makes them harder to distinguish from built-ins
and that way trades decoration for understanding. Looks silly to me, to say the least. The language doesn't distinguish builtins from overriden builtin functions via parens, so the riddle remains for the beholder.
Besides, at the place where I work, they cruft perl in a C fashion, and the coding guidelines require parens even for builtins, so "people with less expertise in perl feel familiar and know what's happening" - which statement makes me cringe. A two hour talk would give them FMTTEWTK about parens, functions and context to get perl basics right and feel at ease with parens just as needed.
Oh, and parens around arguments for builtins even don't work always. Take print. Much has been argued against the current implementation of print. I am glad that it is as it is. At least it gives me an argument against folly.